From 9dc511e46d5acad665175981f824288062e27671 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Wed, 15 Mar 2006 01:31:26 +0000
Subject: [PATCH] url: Allow `;' to separate key/value pairs in URL-encoded
 strings.

The RFC recommends this be allowed, because `&' is special in HTML.
It's also used by various CGI scripts.
---
 url.c | 21 +++++++++++++--------
 url.h |  9 ++++++---
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/url.c b/url.c
index f7e11b3..2dc1c50 100644
--- a/url.c
+++ b/url.c
@@ -112,7 +112,7 @@ static void encode(url_ectx *ctx, dstr *d, const char *p)
 void url_enc(url_ectx *ctx, dstr *d, const char *name, const char *value)
 {
   if (ctx->f & URLF_SEP)
-    DPUTC(d, '&');
+    DPUTC(d, (ctx->f & URLF_SEMI) ? ';' : '&');
   encode(ctx, d, name);
   DPUTC(d, '=');
   encode(ctx, d, value);
@@ -130,11 +130,12 @@ void url_enc(url_ectx *ctx, dstr *d, const char *name, const char *value)
  * Use:		Initializes a URL decoding context.
  */
 
-void url_initdec(url_dctx *ctx, const char *p) { ctx->p = p; }
+void url_initdec(url_dctx *ctx, const char *p) { ctx->p = p; ctx->f = 0; }
 
 /* --- @decode@ --- *
  *
- * Arguments:	@dstr *d@ = pointer to output string
+ * Arguments:	@url_dctx *ctx@ = pointer to the context
+ *		@dstr *d@ = pointer to output string
  *		@const char *p@ = pointer to input data
  *		@int eq@ = whether to stop at `=' characters
  *
@@ -143,7 +144,7 @@ void url_initdec(url_dctx *ctx, const char *p) { ctx->p = p; }
  * Use:		Does a URL decode.
  */
 
-static const char *decode(dstr *d, const char *p, int eq)
+static const char *decode(url_dctx *ctx, dstr *d, const char *p, int eq)
 {
   if (!*p)
     return (0);
@@ -152,8 +153,11 @@ static const char *decode(dstr *d, const char *p, int eq)
       case '=':
 	if (eq)
 	  return (p);
-	DPUTC(d, *p);
-	break;
+	goto boring;
+      case ';':
+	if (ctx->f & URLF_SEMI)
+	  return (p);
+	goto boring;
       case 0:
       case '&':
 	return (p);
@@ -171,6 +175,7 @@ static const char *decode(dstr *d, const char *p, int eq)
 	}
       }
       default:
+      boring:
 	DPUTC(d, *p);
 	break;
     }
@@ -195,7 +200,7 @@ int url_dec(url_dctx *ctx, dstr *n, dstr *v)
   size_t l = n->len;
 
 again:
-  if ((p = decode(n, p, 1)) == 0 || *p == 0)
+  if ((p = decode(ctx, n, p, 1)) == 0 || *p == 0)
     return (0);
   if (*p != '=') {
     p++;
@@ -203,7 +208,7 @@ again:
     goto again;
   }
   p++;
-  if ((p = decode(v, p, 0)) == 0)
+  if ((p = decode(ctx, v, p, 0)) == 0)
     return (0);
   DPUTZ(n);
   DPUTZ(v);
diff --git a/url.h b/url.h
index be38bdc..6f82d12 100644
--- a/url.h
+++ b/url.h
@@ -46,14 +46,17 @@ typedef struct url_ectx {
   unsigned f;
 } url_ectx;
 
-#define URLF_SEP 1u
-#define URLF_STRICT 2u
-#define URLF_LAX 4u
 
 typedef struct url_dctx {
   const char *p;
+  unsigned f;
 } url_dctx;
 
+#define URLF_SEP 1u
+#define URLF_STRICT 2u
+#define URLF_LAX 4u
+#define URLF_SEMI 8u
+
 /*----- Functions provided ------------------------------------------------*/
 
 /* --- @url_initenc@ --- *
-- 
2.11.0